FISH. 1 55 



Family.— BALTSTID^. 

 I . Balistes Vetula. JBl. 



Balistes Vetula, Block, Icbth. tab. 150. 



■ Duperrei/, (Voyage) Zoologie, p. 1 14, pi. 9. fig. 2. 



Form. — Body deep, subrhombic, very much compressed; the greatest depth equalling half the 

 entire length. Tail unarmed. Three or four larger scales than the others behind the bran- 

 chial orifice. Pelvic bone projecting, prickly, connected with which is a fin consisting of 

 about nine pairs of short rays. Above this fin, and parallel to its base, are two or three rows 

 of short spines, but not much developed. First dorsal of three spines, commencing above the 

 pectoral; first spine very strong and rough, the third not much smaller than the second. 

 Second dorsal, and anal, which answer to each other, nearly even throughout, the anterior rays 

 not being prolonged beyond the others. The caudal is injured, and its exact form cannot be 

 determined. No lateral line. 



D. 3—30 ; A. 27 ; C. 12 : P. 14. 

 Length 1 inc. 10 lin. 



Colour. — {In spirits.) Yellowish grey, becoming paler beneath. Three or four dark transverse 

 streaks across the head from eye to eye : beneath the eye one or two indistinct streaks, passing off 

 towards the branchial orifice: also two very distinct longer ones commencing on the upper part 

 of the snout before the eyes, and passing obliquely across the cheeks towards the roots of the 

 pectorals, parallel to those last mentioned. Besides the above, there are several obliquely 

 transverse interrupted lines on the sides of the body : in one specimen, these lines are not well 

 defined ; in another, they are distinct, but so much interrupted as to have the appearance of 

 spots arranged in a linear series. Two or three transverse lines encircling the tail ; and some 

 remains of longitudinal stripes on the second dorsal and anal fins. 



The above description is that of two very small specimens of a species of 

 Balistes taken by Mr. Darwin in Lat. ] 4° 20' South, Long. 38" 8' West, about 

 sixty-five miles from land. I have very little doubt of their being the young of the 

 J5. Vetula of Bloch. The only respects in which they appear to differ from that 

 species are the oblique lines on the back being carried completely across the 

 sides in the form of lines of spots, and the anterior portions of the second dorsal 

 and anal fins not being prolonged in a point ; but both these differences may be 

 the effect of immaturity. 



2. Balistes aculeatus. Hi. 



Balistes aculeatus, Bloch, Ichth. tab. 149. 



Benn. in Zool. of Beecbey's Voy. p. 69. pi. 22. f. 2. 



Form.— Body deep, subrhombic. Tail armed with three rows of prickles, eleven in the uppermost 

 row, about nine or ten in the middle one, and five or six in the lowermost. A few laro-er 

 scales than the others behind the branchial orifice. Pelvic bone very rough and prickly, the 



